Self-contained sewerage system



March 1970 M. E. MINNIEAR ET AL 3,501,778

SELF-CONTAINED SEWERAGE SYSTEM Original Filed March 24, 1967 3 t s t 1FIG-2 IN l/E/V TORS MAX E.MINNIEAR 8: ROBERT C. HELKE A TTORIVEYS March24, 1970 M. E. MINNIEAR ETAL SELF-CONTAINED SEWERAGE SYSTEM OriginalFiled March 24. 1967 3 Sheets-Sheet 5 United States Patent F 3,501,778SELF-CONTAINED SEWERAGE SYSTEM Max E. Minniear and Robert C. Helke,Dayton, Ohio, assignors t Koehler-Dayton, Inc., Dayton, Ohio, acorporation of Ohio Continuation of application Ser. No. 625,647, Mar.24, 1967. This application Feb. 13, 1969, Ser. No. 805,092 Int. Cl. E03d1/00; B61d 35/00; A47k 11/02 US. Cl. 410 6 Claims ABSTRACT OF THEDISCLOSURE A self-container sewerage system for passenger vehicleshaving a unitary thin-walled plastic tank with a rigid bridgereinforcement which supports a substantial portion of the weight imposedon the tank. Reinforcing ribs in the walls of the tank permit the use ofuniformly thin walls throughout without loss of structural integrity.

BACKGROUND OF THE INVENTION This application is a continuation ofapplication No. 625,647 filed on Mar. 24, 1967, now abandoned.

Perhaps the most pertinent art to this invention is the United Statespatents to Dietz et al. No. 3,067,433, issued Dec. 11, 1962 andHerkenhine et al. No. 3,172,131, issued Mar. 9, 1965, both assigned tothe assignee of this invention.

These patents relate to a self-contained sewerage system wherein a flushbowl is supported on the top wall of the tank which normally holds apreset volume of flushing liquid. After the unit is used, the flushingcycle is energized causing the pump to force the flushing liquid fromthe tank upwardly through a manifold surrounding the upper periphery ofthe bowl from where it flows along the inside of the bowl to flush thecontents of the bowl into the tank through a discharge spout. A remotelyactuated valve is provided for draining the contents of the tank at apoint on the exterior of the vehicle in which the unit is mounted, andsimilarly a flushing fluid spray device is provided in the unit forrinsing the tank out as a part of the maintenance operation. The tank ofthis unit is constructed of fiberglass and metal which are securedtogether by conventional fasteners.

SUMMARY OF THE INVENTION This invention relates to a sewerage system ofthe aforesaid type wherein a new compact and lightweight tank isprovided which is molded of a plastic material as a unit and thus is notsusceptible to leakage and whose cost is only a fraction of that of thecomparable prior art. Reinforcing ribs are strategically positioned inthe thin walled tank to make the tank sufiiciently rigid to supportliquid inside together with certain of the lightweight functionalcomponents. A rigid bridge structural nesting in the reinforcing ribs orimbedded in the tank material during molding carries the loadsexternally applied through the flush bowl.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective illustrationof the sewerage system in accordance with the invention,

FIG. 2 is a vertical cross-sectional view taken along the line 2 z ofFIG. 3;

3,501,778 Patented Mar. 24, 1970 FIG. 7 is a bottom view of the tankshowing a portion of the shroud;

FIG. 8 is an enlarged sectional view taken along the line 8-8 of FIG. 2;

FIG. 9 is an end view of the reinforcing shroud showing the tank inbroken lines; and

FIG. 10 is a vertical sectional view through the discharge valve.

DESCRIPTION OF THE INVENTION Referring to the drawings wherein apreferred embodiment of the invention is shown, FIGS. 1 and 2 illustratethe sewerage system which includes an elongated completely enclosed tank10 having the side walls 11 and 12, end walls 13 and 14, and top andbottom walls 17 and 16. A reinforcing shroud or bridge 18 is providedaround and outside the tank 10 for aiding in tthe support of the flushbowl 20. The top wall 17 supports the pump-motor unit 21, the timer 22for the unit 21, the discharge valve assembly 24, the spray tube ormanifold 25, and the bowl 20. When installed, the entire tank 10 and allof the components are covered by a housing (not shown) to improve itsappearance and to protect the user from possible injury. The system isintended for installation in moving vehicles, such as aircraft, buses,and railway passenger cars.

The tank 10 is made of a plastic material, preferably polyethylene, andthus can be molded as a unit with substantial savings in cost andweight. It has been found that the cost is reduced by as much as -90% ofthe cost of tanks now in use. The tank will preferably be formed byrotation or blow molding which creates a tank having thicknesses ofevery surface which are substantially the same. Since the walls arerelatively thin, e.g. to inch, reinforcing ribs or indentations areprovided and in carefully selected positions to aid in supporting theforces imposed upon the tank. The tank is therefore leakproof sincethere are no seams in the corners thereof, is corrosion resistant, andthe time required to assemble the system is reduced since the tank andcover are formed as a unit.

Each of the end walls 31 and 14 is substantially vertical and has a pairof vertical ribs or indentations 27 therein for adding rigidity thereto.These indentations are carefully designed and placed to add maximumstrength to the tank even though the wall thickness is relatively thin.The tank 10 is secured to the supporting surface 28 by the tie-down rodassemblies 30 which include the elongated rods 31 pivotally secured tothe brackets 32 mounted on the surface 28. The upper ends of these rodsfit into slots 34 (FIGS. 3)in the cross member 35 secured to the topwall 17 of the tank by the conventional fasteners 37. Accordingly, whenthe knurled nuts 38 are placed on the threaded upper ends 40 of the rods31 the tank can be clamped to the supporting surface 28. Similarly, thetank can be quickly released by unscrewing the nuts 38 and pivoting therods 31 away from the adjacent end wall 13 or 14. The tie-down rods fitconveniently in the vertical indentations 27 in the associated end wall,and thus do not add to the longitudinal length of the tank 1 0.

The side walls 11 and 12 of the tank 10 are substantially identical andhave a plurality of vertical indentations 41, 42 and 43 therein similarto those in the end walls. The series of indentations 43 are provided inthe area of the bowl 20 since all of the weight of a person sitting onthe bowl 20 must be carried in this area of the tank 10. The indentation41 is provided in alignment with the opening 45 in the top wall 17 whichreceives the pump-motor unit 21, whereas the indentation 42 is inalignment with the opening 47 which receives the discharge valveassembly 24.

The bottom wall 16 of the tank 10 tapers to a discharge opening 50 atthe lowest point in the tank, as seen in FIG. 2, to enable all of thecontents to drain under the force of gravity from the tank. A pluralityof feet 52 are provided on the bottom wall 16 for engaging the surface28 to compensate for the tapered bottom wall 16 of the tank to hold thetank 10 in a horizontal position free from any rocking movement.

As indicated above, the top wall 17 of the tank supports all of thecomponents of the system and it also includes a series of indentationsfor adding rigidity to this wall. The pump-motor unit 21 is thus securedin the opening 45 by inserting appropriate fasteners 54 through theflange 55 on the unit and through the periphery of the circular opening45. A circular indentation 58 surrounds this opening 45 and communicatesthrough the short indentations 61 and 62 with the vertical indentations27 and 41 in the end and side walls thereby adding rigidity to this areaof the top wall 17. The timer 22 for the motor is secured to the crossmember 35 by the connectors 37, and t the unit 21 by the electricalconnector 64. The timer 22 and pumpmotor unit 21 are described in theaforesaid Dietz et a1. patent.

The discharge valve assembly 24 is secured to the top wall 17 in muchthe same manner as the pump-motor unit 21 with the connectors 65 (FIG.extending through flange 66 on the assembly 24 and the periphery of thecircular opening 47. A circular indentation 68 is also provided in thetop wall surrounding this opening and in communication through the shortindentations 70 with the vertical indentations 42 in the side walls 11and 12.

The valve assembly 24 includes a downwardly extending tube 72 secured tothe top plate 73 (FIG. 10) by the connectors 74. The lower tube 75 hasthe valve 76 mounted on the lower end thereof. The rubber ring 77 on thevalve 76 engages the valve seat 78 formed in the bottom wall 16 of thetank in communication with the discharge opening 50. The lower tube 75is adapted to fit snugly inside the upper tube 72 to telescope thereinagainst the bias of the coil spring 80 which is interposed between theupper end 81 of the upper tube 72 and the shoulder 82 formed in thelower tube 75. Accordingly, the lower tube 72 and the valve 76 areconstantly urged down wardly against the valve seat 78.

A vertical bore 84 is provided in the upstanding projection 85 in thelower end of the lower tube 75 to house the coil spring 86 between theupper shoulder 87 and the retainer 88 whose downward movement is blockedby the pin 89. This retainer 88 is connected to the actuator cable 90which extends upwardly through the tubes 72 and 75, through an opening92 in the mounting flange 73, around a pair of pulleys 93 and 94, anddownwardly through the indentation 42. The end of this cable isconnected to a remote actuator for opening the valve 76 to empty thetank from a point exterior of the vehicle. The coil spring 86 maintainsa preset amount of tension on the cable 90 after it is connected to theremote actuating mechanism so that there is little or no looseness inthe cable.

The reinforcing bridge 18 is an important part of the invention andextends around the tank 10 in the area of the indentations 43 shown inFIG. 4. The bridge includes a top plate 100 which covers the elongatedopening 101 in the top wall 17 of the tank and is secured to theupstanding shoulder 102 which defines the elongated opening 101 by aplurality of conventional fasteners 103. The top plate 100 has thecircular opening 104 therein for receiving a portion of the bowl 20, aswill be seen. As

seen in FIGS. 2, 6 and 8 some of the fasteners 1'03 pass' posite edgesof the top plate to add rigidity and strength thereto.

The top plate is supported by the side members 11 which extendvertically downwardly adjacent the side walls 11 and 12 in interlockingengagement with the series of indentations 43 for cooperation therewith.The side members have the horizontal flanges 111 which are disposedadjacent the ends of the elongated opening 101 and support the top plate1'00 which is connected thereto by the conventional connectors 113. Theside members 110 have indentations 115 (FIG. 6) formed therein adjacentthe side edges 116 thereof to engage the complementary projection 43aand indentation 43b in the side walls 11 and 12 while the centralportion 118 thereof spans the two centermost indentations 430. The sidemembers 110 extend downwardly and contact the supporting surface 28 sothat all or most of the weight on the bowl 20 and the forces imposedthereon are transferred directly to the supporting surface through thetop plate 100 and side members 110. A cross member 120 extends betweenthe lower end of the central portions 118 of the side members 110beneath the tank 10 to hold the shroud 18 in place and to maintain theside members 110 in close interlocking engagement with the indentations43.

The reinforcing bridge is thus an important feature of the invention andpermits the use of a relatively thin plastic tank by reason of itscooperation with the indentations 43 and the structure of the tank 10 tosupport the weight imposed upon the flush bowl 20. It is also possibleto mold the bridge partially or entirely within the plastic tank. Thetop plate 100 and side members 110 of the shroud may be made of anysuitable rigid material capable of being formed into the shapeillustrated and supporting the weight present. For example, a moldedfiber glass material has been found to be satisfactory, although itwould be also possible to use various types of metals and rigidplastics. The elongated opening 101 allows the flush bowl 20 to bemounted on either side of the tank 10 thus permitting flexibility ininstallation of the system. It is merely necessary to remove, reverse,and replace the top plate 100 and secure the bowl to the opposite end ofthe elongated opening in substantially the same manner as describedabove.

In operation, the system is installed in an aircraft or other vehiclewith the discharge outlet 50 in the bottom of the tank in communicationwith a conduit leading to a discharge orifice (not shown) in theexterior of the vehicle. Similarly, the spray manifold 25 mounted on theinterior of the tank 10 is connected to a supply conduit through eitherof the connectors 126 (FIG. 2). The tank is filled to a preset depthwith a flushing liquid and thus is ready for use. When it is desired toflush contents from the bowl into the tank, the operator actuates asuitable switch which energizes the pump-motor unit 21 for a preset timeas determined by the timer 22. The unit 21 draws the liquid through thefilter 127 upwardly through the conduit 128 from where it flows from themanifold 129 around the upper periphery of the bowl 20, along the sidesurfaces 130 of the bowl, and through the discharge spout 132 into thetank 10 to wash the contents of the bowl 20 into the tank 10.

When it is desired to empty the unit, a service vehicle or itsequivalent is connected to the discharge conduit 125 and to a supplyline leading to the connector 126. The valve assembly 24 is actuated toopen the valve 76 and allow the contents of the tank 10 to flow underthe force of gravity through the discharge opening 50 and into thedischarge conduit 125. At the same time, the fresh liquid is sprayedthrough the manifold 25 to wash and flush all of the materials from thetank. Once the rinsing operat on is completed, the valve 76 is closedand the tank 10 filled again to the preset level with flushing liquid,and thus is ready for use once again.

The novel tank structure permits a lightweight tank which will supportall of the components of the system,

and cooperates with the reinforcing bridge to support the weight imposedon the bowl. The tank is formed as a single unit, and because of itsspecific design which permits thin walls and the use of plastic, it islighter in weight and much less costly than the conventional stainlesssteel and fiber glass units used heretofore.

While the form of apparatus herein described constitutes a preferredembodiment of the invention, it is to be understood that the inventionis not limited to this precise form of apparatus, and that changes maybe made therein without departing from the scope of the invention.

What is claimed is:

1. A self-contained sewerage system comprising, a closed tank, said tankhaving top, bottom, end walls and side walls and capable of receivingand holding waste material and a flushing liquid, means defining anopening in said top wall, a waste receiving flush bowl mounted on saidtop wall in alignment with said opening and having a discharge spout tothe interior of said tank to direct the waste material from said bowlthrough said discharge spout and into said closed tank, and areinforcing bridge around and outside said tank or molded partially orentirely within said tank carrying the weight of said bowl and at leasta substantial portion of the load applied to said bowl, said reinforcingbridge having top plate means secured to said bowl, side members securedat the opposite ends of said top plate means and downwardly adjacentsaid side walls of said tank, and said side members having lower endswhich engage a support surface so that the weight imposed on said bowlis transferred to such support surface and is not carried entirely bysaid tank to provide additional support for said top plate meansindependent'of said top and side walls of said tank.

2. A self-contained sewerage system as defined in claim 1, wherein anupstanding shoulder portion is provided in said top wall for supportingsaid bowl above said top wall, and means for interconnecting said bowl,said bridge and raised shoulder.

3. A self-contained sewerage system as defined in claim 1, wherein aplurality of vertically extending indentations are provided in said sidewalls in front of and behind said bowl to add rigidity and additionalsupport for the weight imposed upon said bowl.

4. A self-contained sewerage system as defined in claim 3 wherein saidreinforcing indentations include a plurality of vertical indentations ineach of said end and side walls for adding rigidity to said tank.

5. A self-contained sewerage system as defined in claim 1, wherein aplurality of openings are provided in said top wall for receiving andsupporting the components of the sewerage system, and a generallycircular indentation surrounding each of said openings for addingrigidity thereto supporting said components entirely on said top wall.

6. A self-contained sewerage system as defined in claim 1 wherein saidopening in said top wall is elongated, said top plate means has acircular opening therein above which said flush bowl is supported, saidtop plate being reversible end for end and capable of positioning saidbowl adj acent the opposite sides of said tank.

References Cited UNITED STATES PATENTS 2,027,083 1/1936 Baer 2'20-472,298,293 10/ 1942 Hothersall 220-47 2,365,080 12/1944 Humphreys 244-1352,381,400 8/1945 Stavely et al. 244-135 2,508,906 5/1950 Cunningham etal. 244-135 2,838,261 6/1958 Amos et a1. 244-135 2,899,096 8/ 1959Henchert et al. 220-47 3,057,588 10/1962 Kolbe 244-135 3,067,433 12/1962Dietz et al. 4-115 3,147,941 9/1964 Hawthorne 244-135 3,172,131 3/1965Herkenhine et al. 4-115 3,289,214 12/ 1966 Corliss 4-115 FOREIGN PATENTS157,812 7/ 1954 Australia.

530,525 12/ 1940 Great Britain.

533,510 12/ 192.1 France. 1,300,510 6/1962 France.

LAVERNE D. GEIGER, Primary Examiner D. MASSENBERG, Assistant ExaminerUS. Cl. X.R. 4-8,

